If you're a loafer, you avoid working whenever possible, preferring to lounge around relaxing instead. And, if you're too lazy to tie your own shoes, you may prefer to wear loafers — slip-on shoes without laces.
If you're a loafer at work, your co-workers will grow to resent you for doing nothing while they do their jobs. Loafers like to loaf, or "spend time in an idle, aimless way." People will call you a loafer if you spend most of your time in a reclining position, take frequent breaks for snacks and naps, or obviously avoid anything resembling hard work. This noun has been in use since the mid-1800s, but its origin isn't clear. The shoe called a loafer got its name because it's easily slipped on, without the work of laces and knots.